495 research outputs found

    Curvature singularity of the distributional BTZ black hole geometry

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    For the non-rotating BTZ black hole, the distributional curvature tensor field is found. It is shown to have singular parts proportional to a δ\delta-distribution with support at the origin. This singularity is related, through Einstein field equations, to a point source. Coordinate invariance and independence on the choice of differentiable structure of the results are addressed.Comment: Latex, 7 page

    Análisis del ciclo de vida de un edificio con estructura de madera contralaminada en Granada-España

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    A residential building with cross-laminated timber structure in Granada (Spain) was analyzed using the life cycle assessment methodology, life cycle energy analysis and sensitivity analysis to changes in efficiency of operating energy, materials database, transport distances and different scenarios for C&DW. The environmental impacts of the materials and construction production and embedded energy were relatively significant. The global warming impact category was very low due to the CO2 sequestration of wooden materials. Sensitivity analysis revealed that the most significant reduction in environmental impact was achieved through improvements in energy efficiency, high uncertainty in the impacts of the environmental product declaration, the low effect of long-distance transport on the overall impact and the feasibility of the objective of recovery of the Waste Framework Directive by 2020 (above 70%).Se ha estudiado un edificio residencial con estructura de madera laminada en Granada (España) con la metodología de análisis del ciclo de vida, análisis energético del ciclo de vida y análisis de sensibilidad a cambios en la eficiencia energética durante el uso, bases de datos, distancia del transporte y diferentes escenarios para los residuos. Los impactos ambientales de las etapas de producción de materiales y construcción, así como la energía embebida fueron relativamente significantes. El valor del calentamiento global ha sido muy bajo debido al secuestro de CO2 por la madera. El análisis de sensibilidad ha revelado que la mayor reducción se consigue con la mejora de la eficiencia energética, la alta incertidumbre en los impactos de las declaraciones ambientales de producto, el escaso efecto del transporte de larga distancia sobre los impactos totales y la viabilidad de conseguir el objetivo de valorización de la Directiva Marco para el horizonte 2020 (mayor del 70%).This research has been funded by the research contract: “Riesgo y sostenibilidad en los proyectos de ingeniería y edificación” (Fundación Universidad de Granada – UCOP Construcciones, SA, contract No. 3418-00). Construction Project & Site Data have been provided by Bonsai Arquitectos (Mr. Llopis) and Invesia Corporación

    Exploiting the efficacy of Tyro3 and folate receptors to enhance the delivery of gold nanoparticles into colorectal cancer cells in vitro

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    Colorectal cancer (CRC) is the fourth most common cancer in the world. Due to its asymptomatic nature, CRC is diagnosed at an advanced stage where the survival rate is <5%. Besides, CRC treatment using chemotherapy, radiotherapy and surgery often causes undesirable side-effects. As such, gold nanoparticles (GNPs) are envisaged in the field for the diagnosis and treatment of CRC. GNPs have unique physical, chemical and electrical properties at the nanoscale which make them suitable for application in biomedicine. However, for GNPs to become clinically effective, their internalisation efficiency in cancer cells must be enhanced. Folate receptor-α (FR) is overexpressed in CRC cells wherein FR helps in the uptake of folic acid within the cells. Tyro3, a novel tyrosine kinase receptor, drives cell proliferation and its overexpression is correlated with poor prognosis in CRC. Their upregulated expression in CRC cells relative to normal cells makes them an ideal target for GNPs using active targeting. Therefore, in this study receptors FR and Tyro3 were simultaneously targeted using specific antibody-coated GNPs in order to enhance the uptake and internalisation of GNPs in CRC cells in vitro. Four different types of coated-GNPs were synthesised GNPs-PEG, GNPs-anti-FR, GNPs-anti-Tyro3 and GNPs-anti-(FR + Tyro3) and incubated (0–50 ng) with three CRC cell lines namely CRL1790, CRL2159 and HCT116. Simultaneous targeting of these receptors by GNPs-anti-(FR + Tyro3) was found to be the most effective in internalisation in CRC cells compared with GNPs targeted singly to FR or Tyro3 (p <0.05). Besides this, results show that Tyro3 mediated similar internalisation efficacy to FR (p <0.05) in CRC cells using ICP-OES

    Covariant Duality Symmetric Actions

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    A manifestly Lorentz and diffeomorphism invariant form for the abelian gauge field action with local duality symmetry of Schwarz and Sen is given. Some of the underlying symmetries of the covariant action are further considered. The Noether conserved charge under continuous local duality rotations is found. The covariant couplings with gravity and the axidilaton field are discussed.Comment: 9 pages, revtex, no figures; (To appear in Physical Review D

    The potential for operational monitoring of selectively logged forest using vegetation index in the brazilian Amazon.

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    This work presents a approach for monitoring forest degradation in the Brazilian Amazon using a multi-temporal dataset of Landsat-8 imagery. We use a Normalized Burned Ratio (NBR) for detecting selective logging in two differents areas in the Brazilian Amazon, Acre State and the Roraima State. The proposed approach can be used for monitoring forest degradation to availability the vegetation indice using the proposed method and facilitating the implementation of action of forest protection in the Brazilian Amazon.Editores: Douglas Francisco Marcolino Gherardi; Ieda Del'Arco Sanches; Luiz Eduardo Oliveira e Cruz de Aragão
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